Sometimes things have consequences all out of proportion to what we expect. In my list, Catherine O’Leary’s cow is reputed to have kicked a kerosene lantern in 1871 and thereby cause the Great Chicago Fire, resulting in the death of some 300 people and the destruction of about a third of the city’s value. Gavrilo Princip was a 19-year-old man who assassinated Archduke Franz Ferdinand of Austria, setting off a series of events that resulted in the Great War of 1914 – 1918.

And the poor hired hand? The story goes that one day when Wayne Wheeler was a boy, he was working on his family’s farm and his leg was poked by the hayfork of a drunken worker. It traumatized him and he spent much of his life devoted to the abolition of alcohol, becoming the de facto leader of the Anti-Saloon League. His efforts, organizing churches and other small temperance groups to implement a particularly effective form of pressure politics were instrumental in bringing about passage of the Eighteenth Amendment to the U.S. Constitution prohibiting “the manufacture, sale, or transportation of intoxicating liquors” within the U.S. He claimed to have substantially written the National Prohibition Enforcement Act (a fact that the Act’s official author, Andrew Volstead, repeatedly denied) establishing executive power to enforce the Eighteenth Amendment. The full text of the Volstead Act can be found here.

During the 13 years that prohibition was in effect in the United States, alcohol consumption dropped by an estimated 30 percent as legal avenues for access disappeared and costs through illegal avenues rose higher than many people could afford. It is generally accepted that the consequences of this experiment were mostly a flagrant contempt for the law and the rampant creation of illegal alcohol-distribution mechanisms.

What is sometimes forgotten is the role that physicians played in maintaining access to alcohol. They provided one of the few legal ways to obtain alcohol since the Volstead Act carved out an exception to “use liquor for medicinal purposes when prescribed by a physician.” The alcohol prescription pads of the time look almost quaint today, with alcohol consumption as much a part of modern society as it was in the time before prohibition. The idea of drugstores maintaining shelves of government-produced whiskey to dispense to those with prescriptions strikes our current mindsets as almost amusing. It seems obvious to have been an exercise in futility trying to suppress a product so pervasively a part of the prevailing culture.

The experiment on marijuana prohibition may similarly be coming to end, although that experiment has lasted far longer than the prohibition of alcohol. In the early 1900’s, marijuana had been almost unknown in the United States, but it started to become more popular as Mexicans immigrated into the U.S., prompting efforts to ban it. In these efforts, California has always been key, leading the way as other states progressively followed.

California was the first state to ban marijuana in 1913, with many other states following in due course thereafter. California was also the first state to soften its stance on marijuana consumption, allowing medical uses in 1996. Again, many other states followed in due course. And in next week’s election, California may again lead the way in fully relegalizing marijuana with its Proposition 19. A copy of the text of the proposition may be found here. It is worth noting that efforts to fully legalize marijuana in Alaska have failed, even though a 1975 case found personal use of marijuana at home protected by an unusually strong privacy provision in the Alaska Constitution.

In many ways, the currently availability of marijuana for medical purposes in a number of States mirrors what occurred during the era of alcohol prohibition, although marijuana is probably recognized for more legitimate medical purposes than alcohol. During the period of alcohol prohibition, the availability of medical prescriptions made a mockery of prohibition efforts. To be certain, there were many who believed in the therapeutic value of alcohol and there are genuine medical treatments to be had with alcohol, but most prescriptions were filled simply so that people could experience its intoxicating effects. Similarly today, many believe that medical prescriptions for marijuana make a similar mockery of efforts to prohibit its use more generally. Again, there are legitimate therapeutic uses for marijuana, but an honest assessment of medical-marijuana laws is that they have been used as a wedge to gain legal access to its psychoactive properties.

Even if California relegalizes marijuana in next week’s vote, there is still the matter of federal drug-regulation statutes, which prohibit the use of marijuana throughout the United States. In addition to the banning of marijuana use by several states, the federal government began to regulate its use nationally with passage of the Marijuana Tax Act in 1937. A copy of the Act’s text may be found here. What is perhaps interesting about the Marijuana Tax Act is that it included a specific exception for medical uses prescribed by physicians.

The current Controlled Substances Act, which was passed in 1970 in response to President Nixon’s declaration of a “war on drugs” and supplanted the Marijuana Tax Act, includes no such exception. A conflict thus exists between federal and state law in the several states where medical uses of marijuana are permitted under state law. The conflict was tested shortly after California decriminalized such uses in 1996 in the case of Gonzales v. Raich. A copy of the full opinion can be read here. While the case confirmed the authority of the federal government to ban the use of marijuana even in states that have approved it for medical purposes, the policy of the Obama administration has been not to enforce the federal ban with respect to medical users.

The ultimate impact of California’s decision next week will be interesting and may well take years to understand fully. But one thing is certain: if the proposition passes, it is a certainty that similar proposals will be tried in other states and that additional pressure will be brought to bear on the federal government to follow the lesson of prohibition to its ultimate conclusion.